From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B4CFC4360C for ; Fri, 4 Oct 2019 06:23:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5176621848 for ; Fri, 4 Oct 2019 06:23:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="j3noHD8t" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5176621848 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=nMPV76+SE547N8VJaWfK1uIFQ44s/muBnyzkpvAJxfs=; b=j3noHD8tiZasCJ vi/VBjEpRoIyyPIpuMPmRdGc4k/rZybmR5rHIZa8C8CYolN4xpjIBykbVsuj/Gvn1Fysy7kVRMhvB YET4q3EOCqgaA0kU8x33hp65i5S1WXRraE1cDVi+WTxFkpp3/mR7GXTx++d/ckamJ4k6NxXK2DB46 1GRDHBKyN7JeOTrDhWo4ZI7QDkZ5zc+8xUsJhcJh/Xx234NJpFIPx0ZRacv7VrU8T/DBqYPnu0Fbn hp3TJMK7NRYwNlJRc3B4wfBnM+lS4MDadXsOH9vmg0HUIGBHmH6qPMVGFHuo9KybUIav8M0sxMS/y F+Xq036l9sEt31TGqtBg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGH0I-0005Zd-UE; Fri, 04 Oct 2019 06:23:50 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGH0F-0005Yx-MQ for linux-arm-kernel@lists.infradead.org; Fri, 04 Oct 2019 06:23:49 +0000 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iGH08-0002b5-Iz; Fri, 04 Oct 2019 08:23:40 +0200 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1iGH04-0005Rk-Dy; Fri, 04 Oct 2019 08:23:36 +0200 Date: Fri, 4 Oct 2019 08:23:36 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Yizhuo Subject: Re: [PATCH] pwm: stm32: Fix the usage of uninitialized variable in stm32_pwm_config() Message-ID: <20191004062336.jidzrytx4z5talro@pengutronix.de> References: <20191004044649.2405-1-yzhai003@ucr.edu> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191004044649.2405-1-yzhai003@ucr.edu> User-Agent: NeoMutt/20170113 (1.7.2) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191003_232347_733515_CBA441B8 X-CRM114-Status: GOOD ( 12.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, Alexandre Torgue , linux-kernel@vger.kernel.org, Thierry Reding , Maxime Coquelin , Fabrice Gasnier , linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello, On Thu, Oct 03, 2019 at 09:46:49PM -0700, Yizhuo wrote: > Inside function stm32_pwm_config(), variable "psc" and " arr" > could be uninitialized if regmap_read() returns -EINVALs. > However, they are used later in the if statement to decide > the return value which is potentially unsafe. > = > The same case happens in function stm32_pwm_detect_channels() > with variable "ccer", but we cannot just return -EINVAL because > the error code is not acceptable by the caller. Aslo, the variable s/Aslo/Also/ > "ccer" in functionstm32_pwm_detect_complementary() could also be s/functionstm32_pwm_detect_/function stm32_pwm_detect_/ > uninitialized, since stm32_pwm_detect_complementary() returns void, > the patch is not easy. active_channels() is also affected. Also there are calls to regmap_update_bits which should have their return values checked. While a patch to fix these all is not trivial it is certainly possible and I would prefer to fix the problem completely. Best regards Uwe -- = Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | http://www.pengutronix.de/ | _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel